Micro-composite pattern lens, and method for manufacturing same

ABSTRACT

The present invention relates to a micro-composite pattern lens and to a method for manufacturing same. The micro-composite pattern lens of the present invention has a micro-composite pattern with one or more protrusions formed on one side of the lens having a predetermined curvature, and optical polymer nanoparticles arranged in the lens. The micro-composite pattern of the lens may form a wider angle of light emission, thus enabling an LED source, which is a point light source, to be converted into a surface light source having superior luminous intensity uniformity. The lens of the present invention is advantageous in that a single lens may serve as a light guide plate, a prism plate, and a diffusion plate, this eliminating the necessity of stacking optical plates, which might otherwise be required for conventional backlight units. According to the present invention, the angle of emission of the LED source which is approximately 90 degrees can be widened to 160 degrees or higher, and the local change in the micro-pattern and the mixture of ultrafine particles may improve the luminous intensity uniformity and the angle of emission of the light source. Also, wafer levels can be manufactured using a microfluidic channel array based on three dimensional molding techniques and the mixture of ultrafine particles. In addition, the use of single lens having a wider angle of light emission reduces the number of LEDs, thus reducing manufacturing costs and heat generated by LEDs. Further, the micro-composite pattern lens of the present invention has a double curvature structure to achieve improved luminous intensity uniformity and an improved angle of light emission as compared to a single curvature structure.

TECHNICAL FIELD

The present invention relates to micro-composite pattern lens; and, moreparticularly, to micro-composite pattern lens and a method formanufacturing the same which causes the light emitted from the lightsource to have a wider angle of light emission and superior luminousintensity uniformity.

BACKGROUND ART

At present, various technologies have been developed to control thelight by deforming a surface of the lens using elaborate Micro ElectroMechanical System (MEMS) process. Among them, a research fordistributing the light in a wide and uniform manner has been drawn agreat attention.

Particularly, since there are known many advantages in LEDs (LightEmitting Diodes) backlight units (hereinafter, referred to BLUs) ratherthan BLUs used in existing LCD-TV, the LED BLUs have been commerciallyapplied to TV.

A function of the lens is gradually increasing since diffusivity isimportant in cases of LCD or LED light source for illuminating BLU.However, since domestic LED enterprises import the LED lens from Europeor Japan or provide the lens in a manner of joint development withforeign enterprises, domestic lens development is an urgent problem.Since brightness depends on lens of LEDs, the technical importancethereof is very large. Further, the lens occupy the weight of 5% or lessin total LED production cost, but it is expected that the cost is higherin a case of high output LED. Particularly, the function of the lens isvery important in the case of LCD BLU, the development of lens having awider angle of light emission is requested in view of a lower cost. Eventhough a prior lens provided over LED has possibly improved the angle oflight emission, there are problems of limiting to control the luminousintensity uniformity and requiring various composite optical plates suchas a light guide plate, a prism plate, a diffusion plate when convertinga point light source such as LED into a surface light source. Since theproduction process cost for each element is higher and accuratepackaging is required, there is a limitation to reduce overallproduction cost and so integrated optical element is requested.

DISCLOSURE Technical Problem

An object of the present invention is to provide a micro-compositepattern lens and method for manufacturing the same which causes thelight emitted from the light source to have a wider angle of lightemission and superior luminous intensity uniformity.

Advantageous Effects

To achieve the object of the present invention, Further, themicro-composite pattern lens according to the present invention can forma wider angle of light emission, thus enabling an LED source, which is apoint light source, to be converted into a surface light source havingsuperior luminous intensity uniformity. Further, the lens of the presentinvention is advantageous in that a single lens may serve as a lightguide plate, a prism plate, and a diffusion plate, thus eliminating thenecessity of stacking optical plates, which might otherwise be requiredfor conventional backlight units. Further, according to the presentinvention, the angle of light emission of the LED source which isapproximately 90 degrees can be widened to 160 degrees or higher, andthe local change in the micro-pattern and the mixture of ultrafineparticles may improve the luminous intensity uniformity and the angle ofemission of the light source. Also, wafer levels can be manufactureusing a microfluidic channel array based on three dimensional moldingtechniques and the mixture of ultrafine particles. In addition, the useof single lens having a wider angle of light emission reduces the numberof LEDs, thus reducing manufacturing costs and heat generated by LEDs.Further, the micro-composite pattern lens of the present invention has adouble curvature structure to achieve improved luminous intensityuniformity and an improved angle of light emissions as compared to asingle curvature structure.

DESCRIPTION OF DRAWINGS

FIG. 1 is a cross sectional view showing a structure of micro-compositepattern lens according to the present invention.

FIG. 2 shows various micro-composite patterns of embodiments ofmicro-composite pattern lens according to the present invention.

FIG. 3 shows a micro-composite pattern lens according to firstembodiment of the present invention.

FIG. 4 shows a micro-composite pattern lens according to secondembodiment of the present invention.

FIG. 5 shows a micro-composite pattern lens according to thirdembodiment of the present invention.

FIG. 6 shows light penetration into the micro-composite pattern lensaccording to the present invention compared to a general micro lens.

FIG. 7 is photos of taking a picture of light distribution in themicro-composite pattern lens according to the present invention comparedto the general micro lens if white light source is incident.

FIG. 8 is photos of taking a picture of luminous intensity distributionin the micro-composite pattern lens according to the present inventioncompared to the prior micro lens are taken.

FIG. 9 shows a light source, a path which light travels in the generaldome-shaped micro lens, and the distribution of the light which passesthrough the general dome-shaped micro lens.

FIG. 10 shows a diffusion plate, a path which light travels in thedome-shaped micro-composite pattern lens and the distribution of thelight which passes through the micro-composite pattern lens of domeshape.

FIG. 11 is photo of taking a picture of the micro-composite pattern lensaccording to the present invention using a Scanning ElectronicMicroscope (SEM).

FIG. 12 is a graph showing a luminous intensity relating to a distanceand a width of a protrusion, and complex conditions of the distance andthe width in the micro-composite pattern lens according to the presentinvention.

FIG. 13 is a process drawing illustrating a method for manufacturing themicro-composite pattern lens according to the present invention.

FIG. 14 is a view showing an apparatus which enables simultaneousmulti-product of the micro-composite pattern lens according to thepresent invention.

FIG. 15 shows the micro-composite pattern lens having double curvaturestructure according to one embodiment of the present invention.

FIG. 16 is a process diagram illustrating a method of manufacturing themicro-composite pattern lens having double curvature structure accordingto one embodiment of the present invention.

FIG. 17 is an SEM image view of the micro-composite pattern lens havingdouble curvature structure manufactured according to one embodiment ofthe present invention.

FIG. 18 is a graph measuring an angle of light emission of the LED lightsource.

FIG. 19 is a schematic diagram in which the micro-composite pattern lensaccording to the present invention is applied to the LED element.

DETAILED DESCRIPTION OF MAIN ELEMENTS

-   -   1: substrate    -   2: micro-composite pattern    -   3: thin film layer    -   10: protrusion    -   20: nano-particle    -   100: lens    -   200: chamber

BEST MODE

The advantages, features and aspects of the invention will becomeapparent from the following description of the embodiments withreference to the accompanying drawings, which is set forth hereinafter.

FIG. 1 is a cross sectional view showing a structure of micro-compositepattern lens according to the present invention.

Referring to FIG. 1, the micro-composite pattern lens according to thepresent invention has a micro-composite pattern with a plurality ofprotrusions 10 formed on one side of the lens 100 and contains opticalpolymer nano-particles arranged in the lens 100, so that the lightpassing through inside of the lens is scattered, reflected anddiffracted by the protrusions 10 thereby to emitting the light widelyand uniformly into the outside of the lens. In other words, the“micro-composite pattern lens” referred herein means a lens havingmicro-composite pattern with the protrusions of various shape formedthereon.

Though the micro-composite pattern lens can be made from materials suchas a ultraviolet curable epoxy resin, a light curable polymer, a ceramicor the like which is a light sensitive polymer, any materials can bebelonged to a range of the present invention as far as it has micropattern formed on one side and any given curvature.

FIG. 2 shows various micro-composite patterns of embodiments ofmicro-composite pattern lens according to the present invention.

Referring to FIG. 2, the protrusions of micro-composite pattern can beconfigured with various shapes such as (a) a circle, (b) a square, (c) atriangle, (d) a hexagon, and (e) a diamond in cross-section ofhorizontal direction thereof.

The protrusions of the above-mentioned shape are successively arrangedto form the micro-composite pattern.

Further, the vertical cross-section of the protrusions can be configuredwith various shapes such as a square, a semi-circle, a triangle and soon.

In this case, the three dimensional shape of the protrusions can bepresented as a cylinder, a semi-spherical, a cone, a square pillar, aquadrangular pyramid, a triangular a pillar, a triangular pyramid and soon.

Herein, the height or the width of the protrusion has diversity over awavelength of irradiating light source for the purpose of controllingthe luminous intensity uniformity. The width of the protrusions ispreferably formed in equal or greater than the wavelength of the lightsource to increase diffraction efficiency.

Herein, the protrusions formed in one side of the lens are not limitedto the above-mentioned shapes, but can be configured with variousshapes.

Further, the micro-composite pattern lens is not limited to shape ofconvex lens or concave lens, but can be manufactured in various shapes.In addition, the shape or size of the protrusions can be arranged invarious forms to form the micro-composite pattern.

Referring to FIGS. 3 and 4, the various embodiments according to thepresent invention will be described.

FIG. 3 shows a micro-composite pattern lens according to firstembodiment of the present invention.

In FIG. 3, (a) is a top view when being viewed from top of the lens, and(b) is a cross-sectional view taken along a vertical directional line ofthe lens.

A plurality of protrusions 10 is patterned on one side surface of thelens 100.

Herein, the surface curvature of the lens 100 with the protrusionsformed on one side thereof is not limited to the convex lens or theconcave lens, but can be manufactured in various shapes. As one example,the surface curvature can be formed in such a way to be convex in anedge portion and concaved as directing toward a center portion of thelens.

More specifically, a thickness H1 of the center portion A of the lens isformed less than a thickness H2 of a point of half the distance from thecenter portion A of the lens to the edge portion C of the lens.

FIG. 4 shows a micro-composite pattern lens according to secondembodiment of the present invention.

In FIG. 4, (a) is a projection view projecting the micro-composite lensformed on one side of the lens surface based on a horizontal line; and(b) is a cross-sectional view taken along a vertical line of themicro-composite pattern lens.

Referring to FIG. 4, the micro-composite lens according secondembodiment of the present invention has cylinder shape protrusions 10 aformed on a surface proximate to the center portion of the lens andsemi-cylinder shape protrusions 10 b formed as directing toward the edgeportion of the lens.

In other words, the protrusions of two or more shapes are formed to makecomposite patterns.

Further, the shape of the protrusion is configured such that theprotrusions of two shapes are different from one another.

The height of the protrusions 10 a is formed higher than that of theprotrusions 10 b.

The foregoing is only for the purpose of explaining one example, and thepresent invention has protrusions of various shapes arranged to form themicro-composite pattern.

FIG. 5 shows a micro-composite pattern lens according to thirdembodiment of the present invention.

Referring to FIG. 5, the micro-composite pattern lens according to thethird embodiment of the present invention has a non-reflective layer 30of micro-composite pattern having a ratio of height to width which isgreater than a ratio of height to width of the protrusions 10 betweenthe protrusions of the micro-composite pattern formed on one side of thelens 100.

Herein, the width of each of the micro-composite patterns is preferablyformed less than wavelength (λ) of the light source emitted and theheight of the micro-composite pattern is

$\frac{\lambda}{4}{\left( {{4n} + 1} \right).}$

Herein, n is 0, 1, 2 . . . .

In this case, the non-reflective layer 30 can be formed on theprotrusions of the micro-composite pattern.

As still another embodiment of the non-reflective layer, micro-thin filmlayer covering the protrusion and lens instead of the micro-compositepattern can be used. In this case, the non-reflective layer can becomposed with one or more micro-thin film layer.

Herein, the non-reflective layer has a thickness which is ¼ of thewavelength of light source as an example and a refractive index lessthan that of the lens, and is made from materials including one or morefrom MgF2, Al2O3, ZrO2, and Parylene. The optimum refractive index ofthe non-reflective layer is a square root of the refractive index of thelens.

The non-reflective layer 30 minimizes the back-reflection in a directionof a LED light source due to multiple reflections.

FIG. 6 shows light penetration into the micro-composite pattern lensaccording to the present invention compared to the general micro lens.

In FIG. 6, (a) shows that the light passing through the lensconcentrates into the center portion of the lens in a case of thegeneral micro lens, whereas (b) shows the reflection and diffraction areestablished at various degrees due the protrusions to form a wider angleof light emission than the general micro lens in a case of themicro-composite pattern lens according to the present invention.

Referring to (c) of FIG. 6, the micro-composite pattern lens accordingto the present invention can have a maximum angle of light emission bycontrolling factors such as a main curvature P1 of the lens, refractiveindex P2 of the lens material, and shape, size, period and aspect ratioof the protrusion 10.

FIG. 7 is photos of taking a picture of light distribution in themicro-composite pattern lens according to the present invention comparedto the general micro lens if white light source is incident.

In FIG. 7, (a) shows light distribution image of the general micro lenshaving convex curvature; and (b) shows light distribution image of themicro-composite pattern lens with micro composite pattern formed on theconvex surface.

It can be appreciated that the light distribution is wider and moreuniform in the micro-composite pattern lens according to the presentinvention than the general micro lens. In this case, even though themaximum intensity of the light is reduced due to refraction patterninduced by the micro-composite pattern, the uniformity of light passingthrough the lens may be improved.

FIG. 8 is photos of taking a picture of luminous intensity distributionin the micro-composite pattern lens according to the present inventioncompared to the prior micro lens are taken.

It can be appreciated that the light intensity distribution of LED lightsource is more uniform in the micro-composite pattern lens according tothe present invention compared to the general micro lens.

FIG. 9 and FIG. 10 are views shown by comparing a path which the whitelight source travels and the distribution of the light after passingthrough it between the micro-composite pattern lens according to thepresent invention and the general dome-shaped micro lens.

FIG. 9 shows that the general white light source travels straight andthe light is not spread out widely but concentrated as can be known fromphoto of (c) taking a picture of the light distribution in front of thelens, whereas FIG. 10 shows that the light passing the lens isconcentrated and spread out again as can be known from photo of taking apicture of the light passing through the general micro lens.

In FIG. 10, it can be appreciated that the light is widely spread outimmediately after passing through the lens from (a) view illustratingthat the light passing through the diffraction grating is spread out and(b) photo taking a picture of the light passing through themicro-composite pattern lens from the side. Further, it can beappreciated that the light is distributed evenly and widely according tothe micro-composite pattern formed on one side of the lens from (c) ofFIG. 10.

FIG. 11 is photo of taking a picture of the micro-composite pattern lensaccording to the present invention using a Scanning ElectronicMicroscope (SEM).

It can be appreciated that from (a) of FIG. 11 of taking a picture ofthe micro-composite pattern lens according to the present invention viathe Scanning Electronic Microscope (SEM) micro protrusions arepatterned, and from (b) of FIG. 11 of magnifying this picture theprotrusions are shaped like micro pillar and a distance between theprotrusions is about 63 μm.

FIG. 12 is a graph showing a luminous intensity relating to a distanceand a width of a protrusion, and complex conditions of the distance andthe width in the micro-composite pattern lens according to the presentinvention. In FIG. 12, the micro-composite pattern lens according to thepresent invention is represented as μCOS-1 to 5 and the dimension ofeach protrusion is represented as white color.

From a case (a) of FIG. 12 in which the distance between the protrusionsis gradually increasing while maintaining the size of the protrusionequal, it can be known that the less the distance between theprotrusions, the more the angle of the light emission and the less theluminous intensity.

From a case (b) of FIG. 12 in which the width of the protrusion isgradually increasing while maintaining the distance between theprotrusions equal, it can be known that the less the width of theprotrusion, the more the angle of the light emission and the less theluminous intensity.

From a case (c) of FIG. 12 comparing both the distance between theprotrusions and the width of the protrusion, it can be known that theless the distance between the protrusions and the width of theprotrusion, the more the angle of the light emission and the less theluminous intensity.

The micro-composite pattern lens with the protrusions formed on one sidein all three cases above-mentioned according to the present inventionhas luminous intensity uniformity, together with wider angle of lightemission as compared to the general dome-shaped micro-lens.

FIG. 13 is a process drawing illustrating a method for manufacturing themicro-composite pattern lens according to the present invention.

It will be explained hereinafter on the method of manufacturing themicro-composite pattern lens according to the present invention. First,the micro-composite pattern 2 is patterned on a substrate 1 to produce atemplate as shown in (a) of the FIG. 13. Herein, a glass substrate maybe used as the substrate 1.

Next, a thin film layer 3 with elasticity is formed on the template tocover the micro-composite pattern 2 as shown in (b). Herein, the thinfilm layer 3 may be generally polymer material with elasticity such assynthetic resin, e.g., Polydimethylsioxane (PDMS).

A thickness of the thin film layer 3 is made higher than a height of themicro-composite pattern 2 thoroughly to cover the micro-compositepattern 2.

Next, the thin film layer 3 is bonded to an opening of a chamber 200 asshown in (c) of FIG. 13.

In this case, the thin film layer can be treated by oxygen plasma beforebonding it to the chamber to remove the foreign materials.

The chamber 200 has a cavity 210 formed inside and a microfluidicchannel 220 formed to connect to the cavity on one side thereof.

Then, the thin film layer 3 is removed from the template.

The thin film layer after removing the template has a patterncomplementary to those of the micro-composite pattern.

Next, the thin film layer is depressed into the inside of the chamber byapplying negative pressure via the microfluidic channel 220 as shown in(d). Herein, said applying the negative pressure means that the airpressure inside the chamber is made lower than the air pressure outsidethe chamber to discharge the air inside into outside.

Next, the depressed portion in the thin film layer 3, covered with theplate 300 is filled with the filler material 100 containing opticalpolymer nano-particle, covered with a substrate 300, and then appliedwith ultraviolet or heat thereby to cure the filler material, as shownin (e).

The filler material 100 may be ultraviolet curable polymer, heat-curablepolymer and ceramic. If the filler material 100 is cured, it is exactlythe micro-composite pattern lens according to the present invention, andsubsequently, the lens is removed from the thin layer film 3 as shown in(f) of FIG. 13.

Subsequently, ultra thin film layer of non-reflective layer is formed onthe lens as necessary. The non-reflective layer can be formed on thethin film layer 3 and cured before filling the filler material 100.

Since as a master used upon molding the lens during process ofmanufacturing the lens according to the present invention is used asilicone-based PDMS which is superior to deform, the original deformablelens master is manufactured and then duplicated using ultravioletcurable resin or thermosetting resin and re-duplicated as PDMS again,which results the fixed mater can be manufactured from the deformablemaster.

Further, the method of manufacturing the lens according to the presentinvention enables several deformable masters to have the samedeformation under the same pressure simultaneously by connecting thedeformable lens masters via microfluidic channel upon fine-molding, asshown in FIG. 14. The inventor realizes that characteristics of the lenssuch as the angle of light emission is improved if it is configured indouble structure, i.e., structure including all curvature structure ofconcave lens and curvature structure of convex lens as shown in (b) ofFIG. 3, as compared with the single curvature structure. Therefore, thepresent invention provides the method of manufacturing themicro-composite pattern lens having double curvature structure withimproved optical characteristics, and the micro-composite compositepatter lens having double curvature structure manufacture using themethod. Hereinafter, the micro-composite pattern lens having doublecurvature structure will be described referring to the drawings.

FIG. 15 is shows the micro-composite pattern lens having doublecurvature structure according to one embodiment of the presentinvention.

Referring to FIG. 15, the micro-composite pattern lens having doublecurvature structure according to one embodiment of the present inventionhas a surrounding convex portion 310 and a center concave portion 320.The micro-composite pattern lens having double curvature structurereduces hot spot of LED light source via concave curvature of theconcave portion 320 and discharge the light widely. Further, the concavecurvature of the center portion can control the angle of the lightdiffracted and increase the luminous uniformity and reflection angle ofthe light. Further the convex curvature of the surrounding portioncouples the light with fine pattern to control the amount of lightreflected from inside.

Hereinafter, the method of manufacturing the micro-composite patternlens having double curvature structure according to the presentinvention will be described.

Production Example

FIG. 16 is a process diagram illustrating a method of manufacturing themicro-composite pattern lens having double curvature structure accordingto one embodiment of the present invention.

Referring to (a) of FIG. 16, a photo-resist was stacked on a substrateand then patterned to make the micro pattern array 2. According to oneembodiment of the present invention, the silicone substrate of 4 incheswas washed and then water remaining over it was evaporated at atemperature of 120° C. for 30 seconds. As a result, chemical residue andorganic contaminants were moved. Further, a bonding force between thephoto-resist and the silicone substrate is improved due to HMDStreatment. Then, AZ1512 (AZ Electronic Materials) which is a positivephoto-resist was applied to the silicone substrate and then spin-coatedat 1500 rmp for 3 seconds and 450 rmp for 30 seconds, which results thatthe photo-resist layer of 1.2 μm is stacked on the silicone substrate.Subsequently, the positive resist is patterned at a mask aligner (MA6,SUSS MicroTec) and then developed by developer chemicals. As a result,the micro-composite array consisted of a plurality of protrusions, i.e.,micro-composite pattern 2 was produced. The shape and dimension of thepatterned protrusions can be variably deformed and changed depending ondesired efficiency of light emission, which is within the range of thepresent invention.

Referring to (b) of FIG. 16, a thin film layer 3 made from material withelasticity was stacked on the micro-composite pattern 2 to cover themicro-composite pattern 2 on the substrate. Herein, the thin film layer3 can be a polymer with elasticity such as synthetic resin, e.g., PDMS(Polydimethylsiloxane). Further, a thickness of the thin film layer 3 ismade greater than a height of the micro-composite pattern 2 thoroughlyto cover the micro-composite pattern 2, and therefore the shape anddimension of micro-composite pattern 2 can be implemented on the thinfilm layer 3.

According to one embodiment of the present invention, using PDMS thinlayer (Sylgard 184, Dow Corning) as the thin film layer 3, it wasapplied, stacked and then spin coated on the micro-composite pattern 2.Before doing the spin coating, anti-stiction coating(Trichloro(1H,1H,2H,2H-perfluorooctly)silane, 97%, Sigma-AldrichProducts Incorporated, St. Louis, Mo.) was performed on themicro-composite pattern 2 to facilitate removing the thin film layerwith elasticity.

Referring to (c) to (e) of FIG. 16, the elastic layer 200 (shown in (c)of FIG. 16) having a cavity 210 of any size formed inside was bonded andattached to the thin film layer (shown in (d) of FIG. 16), and then thesubstrate was removed (as shown in (e) of FIG. 16). According to oneembodiment, the elastic layer 3 was PDMS, a diameter of the cavity is2.6 mm, and microfluidic channel 240 was formed in the cavity. As aresult, the air pressure within the cavity can be controlled by themicro channel 240.

According to one embodiment of the present invention, within the cavity210 a spherical shape portion 230 such as convex lens was provided in anopposite face 200 a which is opposite to the thin film layer 3. Thespherical shape portion 230 preferably has a diameter smaller than thatof the micro-composite pattern 3 based on a center point of the thinfilm layer. The material of the spherical shape portion is UV-curableepoxy resin, but is only one example and the range of the presentinvention is not limited to it.

Referring to (f) of FIG. 16, the thin film layer 3 was depressed intothe cavity 210, more specifically toward the spherical shape portion 230within the cavity 210 by applying negative pressure via the microfluidicchannel. Herein, said applying the negative pressure means that the airpressure inside the cavity 210 is made lower than outside the cavity 210to discharge the air inside into outside. In other words, a differencebetween inside and outside enables the thin film layer 3 of elasticmaterial forming one side of the cavity 210 to be depressed into thecavity 210. In this case, the thin film layer 3 is contact to thespherical shape portion 230 having curvature structure of convex lenshaving given height and size within the cavity, in which partial area,i.e., only center portion of the thin film layer 3 is contact to thespherical shape portion 230. As a result, the center portion of the thinfilm layer 3 has a structure complementary to the curvature shape of thespherical shape portion 230. However, the thin film layer which is notcontact to the spherical shape portion 230, i.e., the surrounding areahas curvature structure depressed into the cavity 230. Therefore, thecurvature structure of the desired center portion can be decidedvariously depending on the contact area of the thin film layer 3 to thecurvature portion 230 and a radius of the curvature.

Subsequently, referring to (g) of FIG. 16, the thin film layer 3 ofso-called double structure which is configured such that the centerportion is spherical-shaped and the surrounding portion is depressedinto the cavity 210 was filled with the filler material 100 containingpolymer nano-particle and covered with another substrate 100, e.g.,glass substrate and then applied with ultraviolet or heat to cure thefiller material 300. The filler material might be ultra-curable polymer,heat-curable polymer, ceramic and so on. Though a photo-curable resin,particularly UV curable resin (Norland Optical adhesive 63, NorlandProducts Incorporated, Cranbury) was used as the filler materialaccording to this embodiment of the present invention, the range of thepresent invention is not limited to it.

If the filler material 100 is cured, it is exactly the micro-compositepattern lens of the present invention, and subsequently the lens isremoved from the thin film layer as shown in (h) of FIG. 16, which issimilar to (f) of FIG. 13. The curing was UV curable according to thisembodiment of the present invention.

The micro-composite pattern lens obtained via the method mentioned abovehas the double curvature structure, i.e., the center portion of concavecurvature and the surrounding portion of convex curvature, with themicro pattern formed on one side of the lens.

FIG. 17 is an SEM image view of the micro-composite pattern lens havingdouble curvature structure manufactured according to one embodiment ofthe present invention.

Referring to FIG. 17, it will be appreciated that the center portion ofthe micro-composite pattern lens and the surrounding portion surroundingit have different structure, so-called double curvature structure andthe micro pattern is formed on one side of the lens.

Experimental Example

A relationship between the curvature structure of the lens and the angleof light emission was analyzed via this experimental example. The angleof the emission light of the micro-composite pattern lens having doublecurvature structure was measured and analyzed using optical power meter.The LED light source was used as a reference example, andmicro-composite pattern lens of concave lens and convex lens having asingle curvature structure was used as comparison example.

FIG. 18 is a graph measuring an angle of light emission of the LED lightsource.

Referring to FIG. 18, it will be appreciated that the micro-compositepattern lens having double curvature structure according to the presentinvention has a wider angle of light emission than the micro-compositepattern lens having single curvature structure.

The experiment result represents that the angle of light emissiondepends on the curvature structure of the lens and particularly thedouble structure is advantageous.

FIG. 19 is a schematic diagram in which the micro-composite pattern lensaccording to the present invention is applied to the LED element.

Referring to FIG. 19, the micro-composite pattern lens (MSL) havingdouble curvature structure according to the present invention isprovided on a plurality of LED light source (point light source) whichis spaced from each other at a predetermined distance. Particularly,since the micro-composite pattern lens having double curvature structureaccording to the present invention achieve improved angle of lightemission, the micro-composite pattern lens having double curvaturestructure provided on each of LED light sources can effectively diffuseand discharge the light emitted from each LED light source.

While the micro-composite pattern lens and the method of manufacturingthe micro-composite pattern lens according to the present invention hasbeen described referring to drawings, it will be apparent to thoseskilled in the art that various changes and modifications may be madewithout departing from the spirit and scope of the invention as definedin the following claims.

1. A micro-composite pattern lens, having a micro-composite pattern withone or more protrusions formed on one side of the lens having apredetermined curvature, and optical polymer nano-particles arranged inthe lens.
 2. The micro-composite pattern lens of claim 1, wherein themicro-composite pattern lens is made from at least one selected from anultraviolet curable polymer, a heat curable polymer and a ceramic. 3.The micro-composite pattern lens of claim 1, wherein a horizontalcross-section of any one of the protrusions is shaped as one of acircle, a square, a triangle, a hexagonal, and a diamond.
 4. Themicro-composite pattern lens of claim 1, wherein a verticalcross-section of any one of the protrusions is shaped as one of asquare, a semi-circle, and a triangle.
 5. The micro-composite patternlens of claim 1, wherein the protrusions are shaped as one of acylinder, a semi-spherical, a cone, a square pillar, a quadrangularpyramid, a triangular pillar, a triangular pyramid, a hexagonal pillar,and a hexagonal pyramid.
 6. The micro-composite pattern lens of claim 1,wherein a width of the protrusion is greater than wavelength of thelight source irradiated.
 7. The micro-composite pattern lens of claim 1,wherein the protrusions are formed in semi-spherical shape in an edgeportion of the lens to improve an angle of light emission and luminousintensity uniformity.
 8. The micro-composite pattern lens of claim 1,wherein a thickness of the micro-composite pattern lens in a half pointfrom a center portion to the edge portion of the micro-composite patternlens is greater than that of the center portion.
 9. The micro-compositepattern lens of claim 1, wherein the micro-composite pattern lensfurther comprises a non-reflective layer of ultrafine pattern which isformed with a size smaller than that of the protrusion between theprotrusions or over the protrusions.
 10. The micro-composite patternlens of claim 1, wherein the micro-composite pattern lens furthercomprises a non-reflective layer consisted of one or more micro-thinfilm layer formed to cover the protrusions and surface of the lens. 11.A method of manufacturing a micro-composite pattern lens having amicro-composite pattern with one or more protrusions having a crosssection of a circle or a polygon formed on one side of the lens having apredetermined curvature, comprising: patterning the micro-compositepattern on a substrate to make a template; forming a thin film layerwith material having elasticity on the template to cover themicro-composite pattern; bonding the thin film layer to an opening of achamber and then removing the thin film layer from the template;applying a negative pressure to the chamber to cause the thin film layerto be depressed into the chamber; forming the lens by filling a fillermaterial containing optical polymer nano-particle over one sidedepressed into the thin film layer; and removing the lens from the thinfilm layer.
 12. The method of manufacturing a micro-composite patternlens of claim 11, wherein the thin film layer is formed with PDMS(Polydimethylsiloxane).
 13. The method of manufacturing amicro-composite pattern lens of claim 11, wherein the substrate is aglass substrate.
 14. The method of manufacturing a micro-compositepattern lens of claim 11, wherein a thickness of the thin film layer ishigher than a height of the micro-composite pattern.
 15. The method ofmanufacturing a micro-composite pattern lens of claim 11, furthercomprising treating the thin film layer with oxygen plasma beforebonding the thin film layer to the chamber.
 16. The method ofmanufacturing a micro-composite pattern lens of claim 11, wherein saidforming the lens further comprises: a first process of filling a fillermaterial of one or more of a ultraviolet curable polymer, a heat curablepolymer and a ceramic over one side depressed into the thin film layer;and a second process of curing the filler material by applyingultraviolet or heat to the filler material.
 17. A method ofmanufacturing a micro-composite pattern, comprising: stacking aphoto-resist layer on a substrate and then patterning it to form amicro-composite pattern array; applying the thin film layer containingmaterial with elasticity to the micro-pattern array to stack it; bondingone side of the elastic layer having a cavity of a given dimension tothe thin film layer; applying a negative pressure to the cavity byreducing an air pressure inside the cavity to cause the thin film layerto be depressed into the cavity; forming the lens by filling the fillermaterial over the thin film layer; and removing the lens from the thinfilm layer, wherein the cavity is provided with a spherical shapeportion having a predetermined height on an opposite face to the thinfilm layer.
 18. The method of manufacturing a micro-composite patternlens of claim 17, wherein the spherical shape portion in the cavity hasa convex lens shape which is protruded into the thin film layer.
 19. Themethod of manufacturing a micro-composite pattern lens of claim 17,wherein a portion of the thin film layer is contact to a surface of thespherical shape portion when the thin film layer is depressed into thecavity.
 20. The method of manufacturing a micro-composite pattern lensof claim 17, wherein a center portion of the thin film layer is contactto a surface of the spherical shape portion and a surrounding portion ofthe thin film layer is not contact to the surface of the spherical shapeportion.
 21. The method of manufacturing a micro-composite pattern lensof claim 17, wherein the micro-composite pattern lens is formed with oneor more of a ultraviolet curable polymer, a heat curable polymer and aceramic.
 22. The method of manufacturing a micro-composite pattern lensof claim 17, wherein the micro-composite pattern lens comprises anoptical polymer nano-particle.
 23. A micro-composite pattern lens,having a micro-composite pattern with a plurality of protrusions formedon one side of the lens and a double curvature structure having acurvature structure of concave lens in a center portion of themicro-composite pattern lens and a curvature structure of convex lens ina surrounding portion.
 24. A LED element comprising the micro-compositepattern lens having the double curvature structure of claim
 23. 25. TheLED element of claim 24, wherein the micro-composite pattern lens havingthe double curvature structure corresponds to each of multiple LED lightsources and one micro-composite pattern lens is provided in each ofmultiple LED light sources.
 26. The LED element of claim 25, wherein thelight emitted from the LED light source is diffused via themicro-composite pattern lens having the double curvature structure.